1. The Field of the Invention
The present invention relates to utilizing an automatically generated Internet protocol (xe2x80x9cIPxe2x80x9d) address in a networked environment. More specifically, the present invention relates to the generation and use of an automatically generated IP address while an IP address server is unavailable or unreliable, and to the determination of whether or not to use the automatically generated IP address once an IP address server becomes available and assigns an Internet protocol address.
2. The Prior State of the Art
In a TCP/IP network, a standard for global network communications, it is necessary for each node or host on the network to have a unique Internet protocol (xe2x80x9cIPxe2x80x9d) address. The IP address, which is a combination of four sets of numbers that are separated by periods, generally includes a network-identifying portion as well as a host-identifying portion to allow for communication between the different nodes.
Historically, IP addresses have been manually assigned or made available through an IP address server. A manually assigned IP address is assigned to a node or host by a network administrator and remains permanent for that node or host. A manual assignment of the IP address requires a minimal amount of networking knowledge by the network administrator in order to track and assure that no conflicting IP address exists on the network, which at times can become a tedious and imperfect task. Moreover, the need for an administrator is undesirable for small networks, such as those found in small business environments.
When an IP address server that is available on the network assigns an IP address, the IP address assignment is made only for the current connection. This assignment in many instances requires additional software and the use of a network administrator, which, as provided above, is undesirable for small networks. Alternatively, protocols exists, such as Dynamic Host Configuration Protocol (xe2x80x9cDHCPxe2x80x9d), which utilize an available IP address server and eliminate the need for a network administrator to manage IP address assignments. (DHCP is defined by RFC 1531 and is incorporated herein by reference.) Still, an assignment of an IP address by an IP address server requires the IP address server to be available. Therefore, if the IP address server is unavailable or unreliable, no valid IP address can be assigned. Hence, the unavailability or unreliability of an IP address server on a TCP/IP network prevents communication between nodes on the network since no valid IP address can be assigned.
Some non-TCP/IP networks include protocols that facilitate automatic network protocol address generation by incorporating a unique identifier, such as the Institute of Electrical and Electronic Engineers (xe2x80x9cIEEExe2x80x9d) 802 Ethernet address, which is commonly found in network interface cards, into the network protocol address. The use of the unique identifier reduces the possibility of conflict with other automatically generated network protocol addresses. However, with respect to a TCP/IP network, the address base for an IP address is too small to include the IEEE 802 Ethernet address, and the use of just a portion of the IEEE 802 Ethernet address will not guarantee a unique address for each node on the network.
The present invention relates to utilizing an automatically generated Internet protocol (xe2x80x9cIPxe2x80x9d) address in a networked environment. More specifically, the present invention relates to the generation and use of an automatically generated IP address while an IP address server is unavailable or unreliable, and to the determination of whether or not to use the automatically generated IP address once an Internet protocol address server becomes available and assigns an IP address.
Embodiments of the present invention allow for the automatic generation of an IP address when an IP address server is unavailable and for the use of the automatically generated IP address. A proposed IP address is generated by selecting a network-identifying portion while deterministically generating a host-identifying portion based on information available to the IP host. By way of example, the IEEE 802 Ethernet address found in a network interface card may be used with a deterministic hashing function to generate the host-identifying portion of the IP address.
The generated IP address is tested on the network to assure that no existing IP host is using that particular IP address. If a conflict exists, which indicates that the IP address already exists, a new IP address is generated. Alternatively, if no conflict exists, the IP host uses the generated P address to communicate over the network and periodically tests for the availability of an IP address server.
When an IP address server becomes available, an embodiment of the present invention includes using the automatically generated IP address even though the IP address server has provided an IP address. This embodiment is particularly valuable when, for example, the IP address server has lost its database or otherwise continues to provide a conflicting IP address. The method includes the identification of whether a conflict exists in the IP address supplied by the IP address server. If a conflict exists, the generated IP address is used to allow communication to take place over the network.
Another embodiment of the present invention also takes place when an IP address server becomes available. As above, an IP address is automatically generated when the IP address server is unavailable. Then, upon an IP address server becoming available, the IP address server provides an IP address. Under such a scenario, this embodiment retains both the automatically generated IP address and the IP address provided by the IP address server. A determination is made to identify the IP address that will be used. By way of example, if the destination device is on the same Local Area Network (LAN), then the generated IP address is used. Otherwise, the IP address provided by the IP address server is used. This embodiment is particularly valuable because under TCP/IP protocol, when a generated IP address is used, the TCP/IP protocol may not perform certain processes that it would otherwise have been performed, such as, by way of example, encryption. Thus, encryption may be foregone in communications within the LAN by using the generated IP address when communicating within the LAN.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.